American university student Otto Warmbier has been released after more than 17 months of detention in North Korea, but has been in coma for over a year.

22-year-old Warmbier is due to arrive home in Cincinnati on Tuesday evening, after a stop at a U.S. military facility in Sapporo, Japan.

The 22-year-old contracted botulism and is in "bad shape", the CNN reported.

"At the direction of President Donald Trump, the Department of State has secured the release," CNN quoted U.S. Secretary of State Rex Tillerson's statement. No further details were provided.

Warmbier's parents, Fred and Cindy, said that they have been told their son has been in a coma since March 2016, and they came to know this only one week ago.

"Otto has left North Korea. He is on Medivac flight on his way home. Sadly, he is in a coma and we have been told he has been in that condition since March of 2016. We learned of this only one week ago," said Fred and Cindy Warmbier in a statement.

They said, "We want the world to know how we and our son have been brutalised and terrorised by the pariah regime" in North Korea.

They also said they are grateful he "will finally be with people who love him."

Warmbier went with a tour group from Beijing to Pyongyang in January 2016 despite U.S. State Department's travel warnings.

Warmbier was detained in January 2016 at the airport in Pyongyang while on his way home. North Korea had accused him of committing "hostile acts" against the regime as Warmbier was found guilty and sentenced in March 2016 to 15 years hard labor.

Three more Americans are detained in North Korea but their fates have been hanging in the balance as Washington does not have a diplomatic mission in Pyongyang.

(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)